U.S. Pat. No. 4,181,386 discloses a stamped and formed electrical connector clip which is intended to be mounted on a circuit board in straddling relationship to a group of circuit board conductors. A plurality of springs extend from the clip and bear against the conductors on the circuit board so that conductors on a flexible cable can be electrically connected to the circuit board conductors by inserting the cable between the springs and the surface of the circuit board. The connector clip shown in U.S. Pat. No. 4,181,386 is such that the springs can be raised from the surface of the circuit board by the use of a suitable tool thereby to permit insertion of the cable under zero insertion force (ZIF) conditions, a desirable feature which minimizes the potential of damage to the film conductors.
Application Ser. No. 73,402 filed Sept. 7, 1979, now U.S. Pat. No. 4,252,392, shows a connector clip of the general class disclosed in the above identified patent having an integral lifting means assembled to the clip for raising the springs from the surface of the circuit board. The provision of a lifting means mounted on the connector clip eliminates the need of a specialized lifting tool when circuitry changes are to be made.
Connector clips, as disclosed in U.S. Pat. No. 4,181,386 are coming into widespread usage and there is increasing interest in clips having a lifting means mounted thereon, or assembled thereto, in accordance with the general teachings of U.S. Pat. No. 4,252,392. There is also a developing need for a connector clip capable of use under circumstances where a relatively large number of cable conductors or film conductors must be connected to an equal number of circuit board conductors, for example, where a cable having 20 conductors thereon must be connected to an equal number of conductors on a circuit board.
The present invention is directed to the achievement of an improved connector clip and a lifting tool which can be assembled to the clip, if desired, to permit insertion of the cable under ZIF conditions. A connector clip in accordance with the invention, can also be used with a separate lifting tool not mounted on the clip, if it is desired to discourage disengagement of a cable from a circuit board by unauthorized procedures or persons. The invention is further directed to the achievement of a connector clip which is capable of connecting a relatively large number of film conductors to an equal number of circuit board conductors.
One form of connector clip in accordance with the invention, comprises a stamped and formed sheet metal member having a rectangular clip bar and having mounting means extending from the ends of the clip bar for mounting the clip on the circuit board in straddling relationship to the circuit board conductors. A plurality of cantilever springs extend from one of the side edges of the clip bar and towards the circuit board conductors. These springs are arcuately formed to provide bearing portions which bear against the circuit board conductors and each spring has a portion extending from the bearing portion towards and past the clip bar. Each spring further has a tool engageable end portion which is proximate to the clip bar. A lifting tool which comprises a relatively simple rectangular member is moveably supported against a clip bar and has side portions that are received between the free end portions of the springs and the surface of the clip bar. When the clip is mounted on a circuit board, the lifting member can be manipulated in the manner of a lever of the second order to raise the free end portions of the springs and thereby raise the bearing portions of the springs from the surface of the circuit board. The cable or other film can then be inserted beneath the clip bar so that the circuit board conductors are in alignment with the film conductors. When the springs are allowed to return to their normal positions by further manipulation of the lifting tool, the springs bear against the film and thereby press the film conductors against the circuit board conductors. The connector clip, although metallic, does not serve an electrical function since the springs bear against the surface of the film rather than the conductors on the film. If desired, the lifting member need not be mounted on the clip but can be kept separate from the clip and held in custody only by those who are authorized to change the circuitry in which the clip is used.